Therapeutics
Insulin mitigates acute ischemia induced atrial fibrillation and sinoatrial node dysfunction ex vivo
Abstract
Acute atrial ischemia is a well-known cause of postoperative atrial fibrillation (POAF). However, mechanisms through which ischemia contributes to the development of POAF are not well understood. In this study, ex vivo Langendorff perfusion was used to induce acute ischemia and reperfusion in the heart in order to mimic POAF. Inducibility of atrial fibrillation (AF) was evaluated using programmed electrical stimulation and confirmed with open-atrium optical mapping. Compared to the control group without ischemia, 25 minutes of ischemia substantially increased the incidence of AF. The right atrium was more susceptible to AF than the left atrium. Administering insulin for 30 minutes before ischemia and during reperfusion with 25 minutes of ischemia greatly reduced the vulnerability to AF. However, insulin treatment during reperfusion only did not show substantial benefits against AF. Optical mapping studies showed that insulin mitigates ischemia-induced abnormal electrophysiology, including shortened action potential duration and effective refractory period, slowed conduction velocity, increased conduction heterogeneity, and altered calcium transients. In conclusion, insulin reduced the risk of acute ischemia/reperfusion-induced AF via improving the electrophysiology and calcium handling of atrial cardiomyocytes, which provides a potential therapy for POAF.
Authors
Huiliang Qiu, Fan Li, Hannah Prachyl, Alejandra Patino-Guerrero, Michael Rubart, Wuqiang Zhu
Abstract
Type 1 diabetes (T1D) is characterized by the autoimmune destruction of insulin-producing beta cells and involves an interplay between beta cells and cells of the innate and adaptive immune systems. We investigated the therapeutic potential of targeting 12-lipoxygenase (12-LOX), an enzyme implicated in inflammatory pathways in beta cells and macrophages, using a mouse model in which the endogenous mouse Alox15 gene is replaced by the human ALOX12 gene. Our finding demonstrated that VLX-1005, a potent 12-LOX inhibitor, effectively delayed the onset of autoimmune diabetes in human gene replacement non-obese diabetic mice. By spatial proteomics analysis, VLX-1005 treatment resulted in marked reductions in infiltrating T and B cells and macrophages with accompanying increases in immune checkpoint molecule PD-L1, suggesting a shift towards an immune-suppressive microenvironment. RNA sequencing analysis of isolated islets and polarized proinflammatory macrophages revealed significant alteration of cytokine-responsive pathways and a reduction in interferon response after VLX-1005 treatment. Our studies demonstrated that the ALOX12 human replacement gene mouse provides a platform for the preclinical evaluation of LOX inhibitors and supports VLX-1005 as an inhibitor of human 12-LOX that engages the enzymatic target and alters the inflammatory phenotypes of islets and macrophages to promote the delay of autoimmune diabetes.
Authors
Titli Nargis, Charanya Muralidharan, Jacob R. Enriquez, Jiayi E. Wang, Kerim B. Kaylan, Advaita Chakraborty, Sarida Pratuangtham, Kayla Figatner, Jennifer B. Nelson, Sarah C. May, Jerry L. Nadler, Matthew B. Boxer, David J. Maloney, Sarah A. Tersey, Raghavendra G. Mirmira
Abstract
Radiation-induced lung injury (RILI) initiates radiation pneumonitis and progresses to fibrosis as the main side effect experienced by patients with lung cancer treated with radiotherapy. There is no effective drug for RILI. Sustained vascular activation is a major contributor to the establishment of chronic disease. Here, using a whole thoracic irradiation (WTI) mouse model, we investigated the mechanisms and effectiveness of thrombopoietin mimetic (TPOm) for preventing RILI. We demonstrated that administering TPOm 24 hours before irradiation decreased histologic lung injury score, apoptosis, vascular permeability, expression of proinflammatory cytokines, and neutrophil infiltration in the lungs of mice 2 weeks after WTI. We described the expression of c-MPL, a TPO receptor, in mouse primary pulmonary microvascular endothelial cells, showing that TPOm reduced endothelial cell–neutrophil adhesion by inhibiting ICAM-1 expression. Seven months after WTI, TPOm-treated lung exhibited less collagen deposition and expression of MMP-9, TIMP-1, IL-6, TGF-β, and p21. Moreover, TPOm improved lung vascular structure, lung density, and respiration rate, leading to a prolonged survival time after WTI. Single-cell RNA sequencing analysis of lungs 2 weeks after WTI revealed that TPOm shifted populations of capillary endothelial cells toward a less activated and more homeostatic phenotype. Taken together, TPOm is protective for RILI by inhibiting endothelial cell activation.
Authors
Jeb English, Sriya Dhanikonda, Kathryn E. Tanaka, Wade Koba, Gary Eichenbaum, Weng-Lang Yang, Chandan Guha
Abstract
Effective, reproducible, and safe delivery of therapeutics into the inner ear is required for the prevention and treatment of hearing loss. A commonly used delivery method is via the posterior semicircular canal (PSCC); however, its specific targeting within the cochlea remains unclear, impacting precision and reproducibility. To assess safety and target specificity, we conducted in vivo recordings of the pharmacological manipulations delivered through the PSCC. Measurements of auditory brainstem response (ABR), vibrometry, and vestibular behavioral and sensory-evoked potential (VsEP) revealed preserved hearing and vestibular functions after artificial perilymph injections. Injection of curare, a mechanoelectrical transducer (MET) channel blocker that affects hearing when in the endolymph, had no effect on ABR or VsEP thresholds. Conversely, injection of CNQX, an AMPA receptor blocker, or lidocaine, a Na+ channel blocker, which affects hearing when in the perilymph, significantly increased both thresholds, indicating that PSCC injections selectively target the perilymphatic space. In vivo tracking of gold nanoparticles confirmed their exclusive distribution in the perilymph during PSCC injection, supporting the pharmacological finding. Together, PSCC injection is a safe method for inner ear delivery, specifically targeting the perilymphatic space. Our findings will allow for precise delivery of therapeutics within the inner ear for therapeutic and research purposes.
Authors
Jinkyung Kim, Jesus Maldonado, Dorothy W. Pan, Patricia M. Quiñones, Samantha Zenteno, John S. Oghalai, Anthony J. Ricci
Abstract
Retinitis pigmentosa (RP) is a complex group of inherited retinal diseases characterized by progressive death of photoreceptor cells and eventual blindness. Pde6a, which encodes a cGMP-specific phosphodiesterase, is a crucial pathogenic gene for autosomal recessive RP (RP43); there is no effective therapy for this form of RP. The compact CRISPR/SaCas9 system, which can be packaged into a single adeno-associated virus, holds promise for simplifying effective gene therapy. Here, we demonstrated that all-in-one AAV-SaCas9-mediated Nrl gene inactivation can efficiently prevent retinal degeneration in a RP mouse model with Pde6anmf363/nmf363 mutation. We screened single guide RNAs (sgRNAs) capable of efficiently editing mouse Nrl gene in N2a cells and then achieved effective gene editing by using a single AAV to co-deliver SaCas9 and an optimal Nrl-sg2 into the mouse retina. Excitingly, in vivo inactivation of Nrl improved photoreceptor cell survival and rescued retinal function in treated Pde6a deficient mice. Thus, we showed that a practical, gene-independent method, AAV-SaCas9-mediated Nrl inactivation, holds promise for future therapeutic applications in patients with RP.
Authors
Zhiquan Liu, Siyu Chen, Chien-Hui Lo, Qing Wang, Yang Sun
Abstract
Airway remodeling is a critical factor determining the pathogenesis and treatment sensitivity of severe asthma (SA) or uncontrolled asthma (UA). The activation of epithelial-mesenchymal trophic units (EMTUs) regulated by airway epithelial cells (AECs) has been proven to induce airway remodeling directly. However, the triggers for EMTU activation and the underlying mechanism of airway remodeling are not fully elucidated. Here, we screened the differentially expressed gene Cathepsin C (CTSC)/dipeptidyl peptidase 1 (DPP-1) in epithelia of SA and UA patients using RNA sequencing data and further verified the increased expression of CTSC in induced sputum of asthma patients which was positively correlated with the severity and airway remodeling. Moreover, direct instillation of exogenous CTSC induced airway remodeling. Genetic inhibition of CTSC suppressed EMTU activation and airway remodeling in two asthma models with airway remodeling. Mechanistically, increased secretion of CTSC from AECs induced EMTU activation through p38-mediated pathway, further inducing airway remodeling. Meanwhile, inhibition of CTSC also reduced the infiltration of inflammatory cells and the production of inflammatory factors in the lungs of asthmatic mice. Consequently, targeting CTSC with compound AZD7986 protected against airway inflammation, EMTU activation and remodeling in asthma model. Based on the dual effects of CTSC on airway inflammation and remodeling, CTSC is a potential biomarker and therapeutic target for SA or UA.
Authors
Lin Yuan, Qingwu Qin, Ye Yao, Long Chen, Huijun Liu, Xizi Du, Ming Ji, Xinyu Wu, Weijie Wang, Qiuyan Qin, Yang Xiang, Bei Qing, Xiangping Qu, Ming Yang, Xiaoqun Qin, Zhenkun Xia, Chi Liu
Abstract
Pulmonary veno-occlusive disease (PVOD) is a rare but severe form of pulmonary hypertension characterized by the obstruction of pulmonary arteries and veins, causing increased pulmonary artery pressure and leading to right ventricular (RV) heart failure. PVOD is often resistant to conventional pulmonary arterial hypertension (PAH) treatments and has a poor prognosis, with a median survival time of 2 to 3 years after diagnosis. We previously showed that the administration of a chemotherapy agent mitomycin C (MMC) in rats mediates PVOD through the activation of the eukaryotic initiation factor 2 (eIF2) kinase protein kinase R (PKR) and the integrated stress response (ISR), resulting in the impairment of vascular endothelial junctional structure and barrier function. Here, we demonstrate that aged rats over one year exhibit more severe vascular remodeling and RV hypertrophy than young adult rats following MMC treatment. This is attributed to an age-associated elevation of basal ISR activity and depletion of protein phosphatase 1, leading to prolonged eIF2 phosphorylation and sustained ISR activation. Pharmacological blockade of PKR or ISR mitigates PVOD phenotypes in both age groups, suggesting that targeting the PKR-ISR axis could be a potential therapeutic strategy for PVOD.
Authors
Amit Prabhakar, Meetu Wadhwa, Rahul Kumar, Prajakta Ghatpande, Aneta Gandjeva, Rubin M. Tuder, Brian B. Graham, Giorgio Lagna, Akiko Hata
Abstract
Patient-specific induced pluripotent stem cell–derived (iPSC-derived) cell lines allow for therapies to be tailored to individual patients, increasing therapeutic precision and efficiency. Bietti crystalline dystrophy (BCD) is a rare blinding disease estimated to affect about 67,000 individuals worldwide. Here, we used iPSC-derived retinal pigment epithelium (iRPE) cells from patients with BCD to evaluate adeno-associated virus–mediated (AAV-mediated) gene augmentation therapy strategies. We found that BCD iRPE cells were vulnerable to blue light–induced oxidative stress and that cellular phenotype can be quantified using 3 robust biomarkers: reactive oxygen species (ROS), 4-hydroxy 2-nonenal (4-HNE) levels, and cell death rate. Additionally, we demonstrated that AAV-mediated gene therapy can significantly reduce light-induced cell death in BCD iRPE cells. This is the first proof-of-concept study to our knowledge to show that AAV-CYP4V2 gene therapy can be used to treat light-induced RPE damage in BCD. Furthermore, we observed significant variability in cellular phenotypes among iRPE from patients with BCD of divergent mutations, which outlined genotype-phenotype correlations in BCD patient–specific cell disease models. Our results reveal that patient-specific iRPE cells retained personalized responses to AAV-mediated gene therapy. Therefore, this approach can advance BCD therapy and set a precedent for precision medicine in other diseases, emphasizing the necessity for personalization in healthcare to accommodate individual diversity.
Authors
Yao Li, Richard R. Yang, Yong-Shi Li, Chun-Wei Hsu, Laura A. Jenny, Yang Kong, Merry Z.C. Ruan, Janet R. Sparrow, Stephen H. Tsang
Abstract
Pediatric diffuse midline gliomas (DMG) with H3-K27M-altered are aggressive brain tumors that arise during childhood. Despite advances in genomic knowledge and the significant number of clinical trials testing new targeted therapies, patient outcomes are still insufficient. Immune checkpoint blockades with small molecules, such as aptamers, are opening new therapeutic options that represent hope for this orphan disease. Here, we demonstrated that a TIM-3 aptamer as monotherapy increased the immune infiltration and elicited a strong specific immune response with a tendency to improve the overall survival of treated DMG-bearing mice. Importantly, combining TIM-3 Apt with radiotherapy increased the overall median survival and led to long-term survivor mice in two pediatric DMG orthotopic murine models. Interestingly, TIM-3 aptamer administration increased the number of myeloid populations and the pro-inflammatory ratios of CD8: Tregs in the tumor microenvironment as compared to non-treated groups after radiotherapy. Importantly, the depletion of T-cells led to a major loss of the therapeutic effect achieved by the combination. This work uncovers TIM-3 targeting as an immunotherapy approach to improve the radiotherapy outcome in DMGs and offers a strong foundation for propelling a phase I clinical trial using radiotherapy and TIM-3 blockade combination as a treatment for these tumors.
Authors
Iker Ausejo-Mauleon, Naiara Martinez-Velez, Andrea Lacalle, Daniel de la Nava, Javier Cebollero, Helena Villanueva, Noelia Casares, Javier Marco-Sanz, Virginia Laspidea, Oren Becher, Ana Patiño-García, Sara Labiano, Fernando Pastor, Marta M. Alonso
Abstract
The cytoplasmic peptide:N-glycanase (NGLY1) is ubiquitously expressed and functions as a de-N-glycosylating enzyme that degrades misfolded N-glycosylated proteins. NGLY1 deficiency due to biallelic loss-of-function NGLY1 variants is an ultrarare autosomal recessive deglycosylation disorder with multisystemic involvement; the neurological manifestations represent the major disease burden. Currently, there is no treatment for this disease. To develop a gene therapy, we first characterized a tamoxifen-inducible Ngly1 knock-out (iNgly1) C57BL/6J mouse model, which exhibited symptoms recapitulating human disease, including elevation of the biomarker GlcNAc-Asn (GNA), motor deficits, kyphosis, Purkinje cell loss, and gait abnormalities. We packaged a codon-optimized human NGLY1 transgene cassette into two adeno-associated virus (AAV) capsids, AAV9 and AAV.PHPeB. Systemic administration of the AAV.PHPeB vector to symptomatic iNgly1 mice corrected multiple disease features at eight weeks post-treatment. Furthermore, another cohort of AAV.PHPeB-treated iNgly1 mice were monitored over a year, and showed near-complete normalization of the neurological aspects of the disease phenotype, demonstrating the durability of gene therapy. Our data suggested that brain-directed NGLY1 gene replacement via systemic delivery is a promising therapeutic strategy for NGLY1 deficiency. Although the superior CNS tropism of AAV.PHPeB vector does not translate to primate, emerging AAV capsids with enhanced primate CNS tropism will enable future translational studies.
Authors
Ailing Du, Kun Yang, Xuntao Zhou, Lingzhi Ren, Nan Liu, Chen Zhou, Jialing Liang, Nan Yan, Guangping Gao, Dan Wang
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